Retractable ball pen latch means



July 30, 1957 H. w. SAMS RETRACTABLE BALL PEN LATCH MEANS Filed Jan. 26,1954 INVENTOR. HERBERT W SAM-S ATTOPNEKS This invention relatesgenerally to retractable ball pens in which a ball point and reservoirunit is retractably arranged so that it may alternatively be withdrawnwithin the pen barrel when not in use or projected from the barrel forwriting, and more particularly, to an improved latch means for holdingthe ball point unit at projected position and releasing it forretraction as desired.

Generally characterized, the latch means of the present inventioncomprises a plunger member arranged to project rearwardly from the penbarrel and slidably disposed. at the rear barrel end for depressioninwardly United States Patent thereof, a pocket clip mounted on the penbarrel and having a rearwardly'projecting latch portion biased laterallyfor releasably engaging and holding the plunger member when depressed,and means within the pen barrel yieldably biasing the plunger member formovement rearwardly when not engaged by the pocket clip latch portion.By this arrangement, the latching action is accomplished exteriorly ofthe pen barrel so as to avoid obstruction of the pen barrel interiorlyby the latch mechanism and thereby allow a ball point and reservoir unitextending throughout the barrel length to be housed therein with aresulting substantially greater capacity in the unit.

The present invention is described in further detail below in connectionwith the accompanying drawings, in which:

Fig. 1 is an elevation of a retractable ball pen incorporating a latchmeans arranged according to the present invention, with the latch meansshown in retracted position;

Fig. 2 is a vertical section corresponding to Fig. 1, but showing thelatch means latched forwardly to hold the ball point and reservoir unitat projected position;

Fig. 3 is an enlarged plan view corresponding to Fig. 1; and

Fig. 4 is an enlarged fragmentary vertical section of the upper portionof the retractable ball pen shown in Fig. 1.

In the embodiment of the present invention shown in the drawings, theretractable ball pen illustrated comprises a barrel housing formed by afront barrel portion 10 and a rear barrel portion 12 assembled at athreaded connection 14 to house therein a ball point and reservoir unitconstituted by an ink reservoir tube 16 fitted at its forward end with aball point element 18. The ink reservoir tube 16 may advantageously beformed of a compressible plastic material and the ball point element 18arranged to bottom at projected position in the writing tip of the frontbarrel portion 12, comparably to the disclosure in copending applicationSerial No. 386,946, filed October 19, 1953, now Patent Number 2,778,337.The use of a plastic ink tube 16 further facilitates its effectivegripping by the latch means of the present invention in the manner notedfurther below.

Projecting rearwardly from the rear barrel portion 12 is a plungermember 20 which is slidably disposed at the 2,800,883 Patented July 30,1957 rear end of barrel portion 12 for depression inwardly thereof. Theforward end of plunger member 20 is formed with an outwardly extendingflange 22 forming an abutment surface in opposed relation to an inwardlyfacing shoulder 24 provided in the rear barrel portion 20 to confine theplunger member 20 at the projected position shown in Fig. 1. The plungermember flange 22 also serves to cooperate with a bias spring 26 bearingagainst the forward 'face thereof from a mounting in the rear barrelportion 12 at an internal ridge 28, and by which the plunger member 20is biased to assume normally the fully projected Fig. 1 position.

A pocket clip 30 is also mounted on the rear barrel portion 12intermediately of its length as indicated at 32 with a latch arm portion34 extending rearwardly therefrom to overlie the rear end of rear barrelportion 12, with' a clearance aperture 36 provided therein so as toallow'projection of the plunger member 20 as seen in Fig. 1. This pocketclip latch arm portion 34 is laterally biased (to the right as seen inthe drawings), so that upon depression of the plunger member 20 it willshift .to engage the rear end of the depressed plunger member 20 andthereby latch plunger member 20 together with ink reservoir tube andball point element 18 at projected position.

In order to facilitate this latching engagement of the pocket clip latcharm portion 34 with the plunger member 20, the plunger member 20 isadvantageously shouldered inwardly adjacent its rear end as at 38, andformed beyond this shoulder 38 with a rounded tip extension of reduceddiameter as at 40, to provide a latching seat at the shoulder 38 on theplunger member 20. Release of the plunger member 20 for return toretracted or fully projected position under the force of bias spring 26is accomplished simply by pressing laterally (to the left as seen in thedrawings) on the pocket clip latch arm portion 34 to align the aperture36 with the longitudinal axis of the plunger member 20.

Because the plunger member 20 is engaged exteriorly by the pocket cliplatch arm portion 34, it may be formed as a tubular cap, to receivetherein and grip for movement therewith the rear end of ink reservoirtube 16, with the rear latching shoulder 38 of the plunger member 20serving internally as a bottoming shoulder for the ink tube 16 andthereby permitting the entire extent of the forward and rear barrelportions 10 and 12 to be used as a hous' ing for the ink tube 16 so thatthe allowable extent of ink tube 16 is substantially increased over theusual arrangement in retractable ball pens.

The present invention has been described in detail above for purposes ofillustration only and is not intended to be limited by this descriptionor otherwise except as defined in the appended claims.

I claim:

1. In a retractable ball pen, the combination with a barrel housing of apocket clip attached intermediately of its length to said barrel housingwith a flexible clip por tion extending forwardly from said attachmentand a flexible latch arm portion extending rearwardly therefrom, theextending end of said latch arm portion being formed laterally tooverlie the rear end of said barrel housing and having an aperturetherein alignable at the longitudinal axis of said barrel housing, and aplunger projecting rearwardly from said barrel housing through saidlatch arm portion aperture and slidably disposed within said barrelhousing for depression inwardly along the longitudinal axis thereof,said plunger being yieldably biased rearwardly with respect to saidbarrel housing and having a shoulder at its rear end with a tip portionof reduced diameter extending rearwardly from said shoulder, and saidlatch arm portion being biased later- 2,800,888 a H I p allyfor;displacing said'aperture and thereby releasably engaging the plungershoulderand retaining saidplunger when depressed.

2. A retractable ball pen comprising a barrel housing formed 1 with aninwardly} facing annular-shoulderadja+ cent the rear end thereoflZ-arearwardlyprojecting plunger end with'an inwardly'stepped shoulderiandaatipiportion of reduced diameter.extending'therebeyond; and a pocket clipmounted intermediately of its length exteriorly on said barrel housingwith a fiexiblelatch arm portion extending rearwardly from saidmounting, the extending end of said latch arm portion being formedlaterally to overlie the rear end of'said barrel housing and having aclearance aperture therein allowing rearward projection of said plungertherethrough, and said latch arm portion being laterally biased forshifting againstsaid plunger shoulder on the side thereof that isopposite the mounting of said pocket clip and thereby releasablyengaging said plunger shoulder upon depression of said plunger todispose the tip portion thereof at said aperture. 7 r a 3. In aretractable ball pen, the combination with a barrel housing of a clipattached intermediately of its length to said barrel housing with aflexible clip portion r. 4 V extending forwardly from said attachmentand a flexible latch arm .portion extending rearwardly therefrom, .theextending end of said latch arm portion being formed laterally tooverlie the rear end of said barrel housing and having an aperturetherein alignable at the longitudinal axis of said barrel housing, and aplunger projecting rearwardly from said barrel housing through saidlatch arm portion aperture .and slidably disposed within said barrelhousing for depression inwardly along the longitudinal axis thereof,said plunger being yieldably biased rearwardly with respect to saidbarrel. housing and having a rearwardly facing shoulder arranged thereonfor engaging said latch arm portion on the side thereof opposite themounting of .said pocket clip, and said latch arm portion beinglaterally biased 'for shifting against said plunger shoulder andreleasably engaging said plunger when depressed.

References Cited in the'file of thislpatent v UNITED STATES PATENTSSwitzerland 'Mar. '2, 1953

